Salman Khan is a famous Indian actor with over two decades of box office success. Recently, another Salman Khan is gaining fame because of a different kind of audience he holds captive. This Salman Khan, or "Sal" as he likes to call himself, is an educator unlike any other you've heard before. Sal runs one of the most popular and prolific online universities in the world, Khan Academy, from his home. Khan Academy is an ever-growing collection of YouTube videos that aim to teach a variety of subjects from math to history and biology to physics.
Sal scribbles down math equations on a digital blackboard and narrates each step of the equation in a very soothing but not boring tone. These lectures last 10-15 minutes and cover a small part of a subject. Currently there are about 140 videos spanning the subject of "Linear Algebra" and I've reviewed the sixth video in the series so far. I am in the process of reviewing a lot of math that I haven't touched since graduating from college six years ago. I plan on doing a lot of independent research over the next 6-12 months and I need to learn a lot of math behind digital signal processing, computer vision, and audio synthesis. That means hundreds of hours of learning calculus, linear algebra, physics, and complex numbers.
I've known about the Khan Academy for many years but didn't bother checking out any videos because I felt it was meant for middle and high school students. Indeed, that is how Sal started making these videos - to help his nieces and nephews with their school work. However, now that I actually want to relearn a lot of stuff I've learnt in the past but forgotten over time, I find Sal's videos to be perfect for me. They are very straightforward, he explains almost every detail, and since it's YouTube, you can rewind or skip sections easily. I watch a 15 minute video in about 8-9 minutes. However, there are some parts I watch 2-3 times if I don't understand them the first time around.
I've been listening to Sal's voice for three days now and I'm certain I will continue to do so daily for the next six months. I looked at a lot of other OpenCourseWare, including free classes by MIT and nothing comes even close in terms of quality to Sal's videos. I think the real reason is that while all the large universities are trying to upload videos of in-class lectures by professors and making books, notes, and exams available online, Sal is concentrating on what matters most - simple and clear instructions in small, digestible doses. An MIT OpenCourseWare lecture on Computer Algorithms is daunting. Each lecture is between 60 and 90 minutes long and contains slides, related content, assignments, exams, projects, multiple downloadable formats, and group discussions. Sal's videos run full-screen and have no distractions, interruptions, or extra work. If you want to truly learn a subject, Sal's videos are what you need. If you want to get the in-school experience of doing homework, assignments, and exams, then get started with OpenCourseWare from any number of universities.
My goal is to learn many different subjects in a short span of time. So in addition to Sal's videos, I'm reading books, writing programs to solve some of the new problems I encounter, and reviewing any scientific papers that interest me. 2011 will be an exciting year for sure. I can't wait to catch up on everything I missed.